1. Field of the Invention
The present invention relates to a color image recording apparatus for recording a colored image on a photosensitive recording medium.
2. Description of the Related Art
One conventional method for recording a colored image on a color photosensitive recording medium (hereinafter also referred to as "photosensitive sheet") employs color separation filters of red (R), green (G) and blue (B) for producing color-separated mask members from an original color image. The photosensitive sheet is exposed to light successively through these mask members. There is also known a process for applying white light directly to a colored original image and exposing a photosensitive sheet to light reflected by the colored original image. The former colored image recording method is more efficient than the latter process in that the intensity of exposure energy required to be applied to the photosensitive recording medium by the former method is much smaller than that required by the latter process.
One inhouse proposal has been made with respect to a color image recording apparatus for electrophotographically producing mask members using toner as a light-shielding substance on a light transmissive sheet, and exposing a photosensitive sheet to light through such mask members for reproducing a colored image on the photosensitive sheet.
Further, a subsequent inhouse proposal has been made (as described in U.S. Pat. No. 4,884,082) regarding a color image recording apparatus for producing mask members using a commercially available monochromatic printer such as a laser beam printer, and reproducing a colored image in the same manner as disclosed in the above proposal. In the recording apparatus disclosed in U.S. Pat. No. 4,884,082, the mask members of red (R), green (G) and blue (B) are printed on ordinary paper sheets of cut form by the monochromatic printer, and monochromatic lights of red (R), green (G) and blue (B) are applied successively to a photosensitive recording medium through the mask members Since the mask members are produced on ordinary plane papers, maintenance and handling of the mask members are facilitated, and the mask members are convenient to use especially when a number of colored images are to be produced using the same mask members or a colored image is to be reproduced at a later time using the mask members.
There has been also another inhouse proposal regarding an image recording apparatus in which mask members produced on respective cut sheets have respective identification marks indicating the colors of the mask members. This apparatus has a sensor for reading the identification marks on the mask members that have been delivered to an exposure position, so that the colors of lights to be applied through the mask members to a photosensitive sheet can automatically be selected so as to correspond to the mask members in use. This apparatus allows the photosensitive sheet to be exposed to light of desired colors irrespective of the sequence in which the mask members may be delivered to the exposure position. Therefore, the mask members may be manufactured in any desired order by a monochromatic printer, and the manufactured mask members may be inserted in any desired order into the color image recording apparatus, since a colored light corresponding to the applied mask member is irradiatable.
Further, in U.S. Pat. No. 4,884,082 which discloses the color image recording apparatus using the mask members, a mask member circulating passage is provided for repeatedly feeding the mask members to the exposure position end for positioning them when a number of colored images are to be reproduced from one set of such mask members. With the mask member circulating passage, it is not necessary to prepare mask members again on a monochromatic printer or to insert the mask members manually into a mask member feeder each time a colored image is to be reproduced. Consequently, color images can be recorded at a high speed.
In some cases, a desired image is not recorded due to the use of a wrong mask member in continuously operating the image recording apparatus to record the same color image on a plurality of image recording media. In such a case, the image recording operation must be interrupted immediately to avoid useless image recording operation. The interruption of the image recording operation is important particularly to the image recording apparatus in view of saving materials because the image recording apparatus consumes mask members and many sheets including photosensitive sheets and developing sheets.
However, the appropriate timing for stopping the image recording apparatus without causing jamming or clogging has been difficult because these sheets are conveyed along a complicated path through the image recording apparatus and different processes are carried out simultaneously. Accordingly, it has been impossible to stop the image recording apparatus before producing a set number of copies.
Naturally, the image recording apparatus can be stopped by opening the main switch or by opening the cover, provided that the image recording apparatus may be stopped regardless of the current condition of the image recording processes. For example, if the image recording apparatus is stopped while the mask member is being changed, the mask member is held at a random position, which often causes jamming. If the mask member is jammed within the image recording apparatus, the jammed mask member must be removed by hand to restore the image recording apparatus to its normal condition. If the image recording apparatus is stopped while conducting a pressure developing process, in which a photosensitive recording sheet and a developing sheet are pressed together, it is possible that the photosensitive sheet and the developing sheet adhere to each other.